Self-priming fluid pump



June 2, 1970 o. PRONI SELF-PRMING FLUID fUMP Filed Aprl 9, 1968 2 Sheets-Sheet l FIG. 2

INVENTOR OSCAR PRONI ATT YS.

Janez, 1970 o. PRONI &5 I I v I SELF'PRIMING FLUID PUMP Filed April 9, 1968 2 Sheets-Sheet 2 04 INVENTOR OSCAR PRON 200 Jm a@ ATTYS.

United States Patent O U.S. Cl. 415-53 3 Claims ABSTRACT OF THE DISCLOSURE A self-priming centrifugal fluid pump having a cylindrical housing, a shaft eccentrically mounted within the housing, an impeller mounted upon said shaft for rotation within the housing, an inlet path through the impeller and an outlet path having its entrance in the vicinity of the shaft, the impeller being of shallow cylindrical configuration and having an entrance, radial passageways leading from the axial entrance to the housing interior and a plurality of secondary axial openings communicating with the :radial passageways with the net eifect that air entering the pump is discharged preferentially from the impeller and from the outlet thereby making the pump self-priming. There further is described a deep-sea fluid samplng head system in which the pump of the invention is advantageously utilized.

B-RIEF SUMMARY OF THE INVENTION This invention relates generally to centrifugal fluid pumps and particularly provides a novel self-priming centrifugal fluid pump having a driven rotatable impeller eccentrically mounted in a housing and provided with a plurality of radial passageways communicating to the pump interior, a like plurality of aXial openings communicating to the radial passageways, whereby fluid pressure differentials are created within the impeller and within the pump interior so that air therewithin can be expelled obviating manual priming of the pump.

Normally, when air enters into the interior of a centrifugal fluid pump and particularly into the impeller of the centrifugal fluid pump, the action of the impeller in forcing fluid therepast ceases as contact between fluid and impeller surface is severed. One cannot operate the pump thereafter to provide discharge of fluid until the pump is primed, that is, the air is removed. Often this corrective measure must be performed manually so that the air .is forced from the pump and the impeller thereof. For many pump applications, this expedient is not advantageous.

Accordingly, it is the principal object of this invention to provide a centrifugal fluid pump that is self-priming.

Another object of this invention is to provide a selfpriming centrifugal fluid pump wherein air trapped within the impeller is expelled without modification of the operation of the pump.

A further object of this invention is to provide a self-priming centrifugal fluid pump wherein air entering the pump will be preferentially expelled during the op eration of the pump by the creation of at least a pair of independent fluid circulation flow paths defined as a result of rotation of the impeller within the housing.

Yet a further object of this invention is to provide a more eflicient fluid pump which can function either as an air pump or a liquid pump.

Yet a still further object of this invention is to provide a self-priming fluid pump of the centrifugal type advantageously useful in deep-sea fluid sampling where manual priming is inopportune.

Other objects and advantages of the novel self-prim- 3,5l5,494 Patented June 2, 1970 ing fluid pump according to the invention will become evident to the skilled artisan as a detailed description of a preferred embodiment thereof is set forth hereinafter with reference to the accompanying drawings.

DESCRIPTION OF THE VIEWS OF THE DRAWINGS FIG. 1 is a reduced perspective view of the self-priming fluid pump according to the invention.

FIG; 2 is a lateral section taken through the rotational axis of the pump shown in FIG. 1. r

FIG. 3 is a transverse section of the pump illustrated in FIGS. 1 and 2 taken along the line represented by lines 3-3 in FIG. 2.

FIG. 4 is a transverse section of the pump illustrated in FIGS. l and 2 taken along a line represented by lines 4 4 of FIG. 2.

FIG. 5 is a schematic flow diagram of a deep-sea particle sampling arrangement utilizing the self-priming fluid pump constructed in accordance with the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT The centrifugal type fluid pump constructed in accordance with the invention briefly is characterized as having several constructional features rendering the same considerably more eflicient in operation than heretofore known.

Among these features are the provision of a shallow, cylndrical impeller mounted for rotation within a housing considerably larger than the impeller. The impeller is provided with a central inlet port or entrance and a plurality of radial passageways. The impeller further is provided with a like plurality of axial openings to the under-surface thereof arranged communicating to the interior or outlet end of the impeller within the pump housing. The impeller is secured to a driven shaft for rotation on an axis parallel to but offset from the housing axis and is seated on a bearing means also providing communication between the inlet or entrance of the impeller and the inlet port of the pump. The self-priming fluid pump according to the invention further includes an outlet having an entrance in the vicinity of the axis of rotation of the shaft and impeller for a purpose to be explained hereinafter. The principal pumping is performed as a result of the centrifugal force created 'by rotation of the impeller directing fluid from the impeller entrance through the radial passageways, along a spirallike current flow adjacent the inner surface of the cylindrical housing to the outlet and further, a second, other current path is developed whereby fluid passes from the housing interior through the axial passageways and thence through the radial passageways and return so that air entering the impeller and trapped at the center thereof can be drawn out and expelled. v

Referring to FIG. 1, the self-priming fluid pump according to the invention is generally designated by the reference character 10 and includes the hollow pump body '12 of generally cylndrical configuration in which an impeller 14 is mounted for rotation within the body 12 on a shaft 16 operably connected through sealed bearing means 18 and coupling means 20 to an exterior mounted motor 22. As shown in FIG. 1, the motor 22 is mounted on a mounting plate 24 and legs 26 thereof are arranged in socket means 28 on the 'body 12.'The pump has an inlet port 30 and an outlet port 32. Second hearing means 34 is disposed between the inlet and the impeller to provide a rotational base for the impeller. Appropriate passageways are provided within the bearing means 34 to provide for communication between the inlet port 30 and the impeller 14.

&515494 The pump body 12 includes a vertical wall 36, a top wall' or cover 38 and a bottom wall or base 40. In the embodiment illustrated, the base 40 and cover 38 are Secured to the cylindrical wall 36 'by fastening means such as screws 42, the cover 38 and base 40 each have a common diametrical dimension and formed with coaxial openings 44 and 46.

The impeller 14 is formed 'of a cylindrical body 48 having a central substantially cylindrical upstanding hub 50. An axial passageway 52 is formed through hub 50. An intersecting transverse passageway 54 also is provided through hub 50. Passageway 52 has a wide mouth portion 56 to define a shoulder 58. A central axial passageway or entrance 60 is provided in the impeller opening to the undersurface 62 thereot. Radial passageways '64 are formed in the body 48 and have outlets 66; passageway 60 functioning as the common inlet to radial passageways 64. A plurality of secondary axial passageways 68 are formed opening to the undersurface 62 of body 48 and communicating with respective ones of the radial passageways 64. The secondary axial passageways 68 are spaced inwardly of the periphery of impeller body 48 but are spaced radially from the aXs of impeller 14 so that web portion 70 results. The diameter of passageways 68 is considerably less than the diameters of passageways 64 and entrance 60.

The shaft 16 has an extension of reduoed diameter 72 terminating in a tapered portion 74. The impeller is arranged in the housing coaxal with passageways 44 and 46. A lower hearing assembly 34 is fitted through passageway 46 of base 40 and consists of an inner hearing 76 threadably engaged within hearing support 78. Suitable packing such as O-rng 80 is provided so as to assure a fluid-tight type seal. The inner hearing 76 is hollow and has a passageway 82. A hearing web 84 blocks of the inner end of passageway 82 except for seoondary passageways 86. The outer end surface of web 84 is provided with a conical recess 88. The apeX of this recess 88 is coaxial with the shaft 16 and extension 72 thereof so that the tapered end 74 of the extension 72 rests in the recess 88. The hearing support 78 has an axal passageway 90 and tapered end portion 92. The clearance area between web 70 of the impeller body 48 and the tapered end 92 of the outer hearing 78 is controlled adjustably by the position of web 84 of the inner bearing, adjustable by virtue of the threaded connection between inner hearing 76 and hearing support 78. A gland 94 is disposed in the outer end of passageway 82 and has a passageway 96 defining the entry port 32 of the pump. The shaft 16 is secured to impeller hub 50 'by means of pin 98 passing through passageway 54.

The upper hearing and guide assembly 20 has outer housing 100, inner hearing 102 and suitable resilient packing 104 to ensure a fluid tight seal. When the pump is in operation, the extension end 74 is maintained in contact with the floor of recess 88 of inner hearing portion 84. Liquid is permitted to pass through the lower bearing 34 by means of inlet port 96, passageway 82, secondary passageways 86, passageway '90 into the central entrance 60 of impeller 14.

When there is no air in the pump, centrifugal force causes a pressure rise which moves liquid from the entrance 60 outwardly through the radial passageway 64 into the interior of body 12. The liquid surrounding the impeller 14 also is caused to rotate but not as fast as the liquid in the immediate vicinity of the impeller 14 'due to frictional losses with the inner surface of cylindrical wall 36 and the layers of liquid as they range outwardly of the impeller 14. The cover 38 has a horizontal through passageway 106 having an entrance 108 opening to passageway 44. The outer end of passageway 106 terminates in`out1et 32, entrance 108 fnctionng as the entrance to the outlet.

It is believed that three forces cooperate to provide the pumping action.

. 4- When the impeller -14 is rotated at high speed, centrifugal force acting upon the liquid contained in the passageways 64 between their outlets 66 and the secondary axial passageways 68 throws the liquid outwardly, creating a pressure rise. In addtion, since liquid is rotating faster at the inside ends of the passageways 68 than at the outside ends, due to frictional losses outside, there is a pressure differential across these passageways which set up circulating currents indicated by the flow lines 120 of FIG. 2. These circulating currents, because of the Bernoulli effect, tend to suck liquid into the stream from the remainder of the passageways 64 between the secondary axial passageways 68 and the inlet 60. In addition, there is the centrifugal force exerted upon the liquid contained in the inner portions of the passageways 64, albeit smaller because of the smaller radius. The sum of these forces causes the liquid to leave the system via the outlet 32 and liquid is dra'wn into the system via the inlet 30 to replace it. Since the liquid is rotating in the body 12 also, there is a retarding centrifugal force, but this is smaller due to its lesser velocity due to frictional losses to the walls of the vessel and because the flow pattern is interrupted by the eccentricity of the impeller.

Now, let us assume a slug of air enters the inlet port 30 through passageways 96 and 82, etc., or for some other reason the interior of the body 12 is not full of liquid, as by previous air entry, as represented by air liquid nterfaces 110 and 112. Due to the rotation of the impeller and frictional forces, the liquid primarily stands in a confined vortex along the sides of the housing 3. Due to the fact that the axis of rotation is offset from the axis of the body 12, that is, the rotation is one of eccentricity relative to the interior of body 12 the liquid is forced to rotate in a fiow pattern of higher velocity on that side of the shaft closest to the wall 36 because of the reduced cross section than on the other Side. Arrows 114, 116 and 118 and arrows 114', 116', 118' illustrate the different flow velocities as represented by the different relative lengths of these arrows. Now, if there is air such as shown in FIG. 2 and represented by letter A, the liquid L being confined to a location adjacent the wall 36; the entrance 108 etfectively is blocked by the air from contact with the liquid. Therefore, if air enters the interior of body 12, it will accumulate around the shaft and will be first expelled. Thus, the device will pump air until same 'is expelled before it pnmps liquid.

Since the body otherwise is filled with liquid L, one must assume that passageway 64 will be filled with liquid. Assuming that there is liquid between the passageways 68 and the end 66 of passageway 64, this liquid will be expelled as a result of centrifugal force. As the liquid will be expelled from end 66 it will be sucked into passageway 64 at the openings 68 so that a circular or substantially circular component in the liquid motion will be generated as illustrated by the streamlines 120, the lines of greatest velocity being those directed through the narrow cross-section openings established by passageway 68. Since there is little resistance in this path for restricting flow, the circulation will be appreciable and at the air-liquid interfaces .112 within the passageway 64, the pressure will be reduced due to the Bernoulli efiect. The air at air-liquid interfaces 112 will be aspirated into this circulaton stream 120 and driven out of the passageways 64 from the center of impeller 14. Thereafter, the air will bubble into the air filled region A. As more air is aspirated by this action the air will be removed from the pump through entrance 108, passageway 106, and outlet 32. Obviously when there is no longer an air-liquid interface at 112 and only liquid enters the pump, no liquid will be expelled from the pump through outlet 32 until all the air has been expelled.

If an anti-backup valve such as the check valve 122 shown in phantom, is installed at the inlet 30, some liquid will remain in the housing so that the pump can function either as an air pump or a liquid pump since once the liquid decreases to a point below a critical level higher than the impeller level, no more liquid can be expelled from the pump.

The pump 10 can be advantageously utilized as a part of a submersible sampling and study system say for deep-sea exploration. One such system utilizes elec- Uonc particle counting and sizing apparatus well known to the art as equipments sold under the trademark Coulter Counter manufactured by Coulter Electronics, Inc. of Hialeah, Fla. Generally, samples of sea water are forced through a restrictive small cross-section current path and changes in the electrical characteristics or in an electrical characteristic of that current path are monitored and analyzed electronically. The pumps 10 are useful in the sampling head on the submersible system as illustrated diagrammatically in FIG. 5. The sample is taken by causing the flow of sea water through filter 200 for removal of particles which may clog the measuring system. Thereafter the sample passes through the sample chamber 202 by path 204, 204' or through bypass 206. The sample chamber 202 is provided with an aperture tube 203 having a microscopic aperture in the lower wall thereof and electrodes and appropriate connection thereto (not shown) are provided as reported in Coulter Pat. 2,656,508. The pressure differential can be checked before submersion by connecting a mercury manometer (not shown) across the aperture by means of the valves 208 and 210. The sea water is sucked by the pump 10 through a needle valve 212 and on, through needle valve 214 back to the sea, as shown in FIG. 5. Some of the sea water passes through the sample chamber 202 to be directed in a path along conduit 216, conduit 218, past a dn'p chamber 220 for electrical isolation and through a normally opened solenoid valve 224 along conduit 222. Another similar pump 10', causes liquid to flow through the sample chamber along conduit 228 and then the sample flow enters the stream to the pump 10 along conduit 230. The needle valve 214 Controls the back pressure, when valve 224 is operated to connect conduit 222 to conduit 231, say for cflushing the aperture tube 203 to dislodge any debris which may have accumulated in the aperture thereof defining the reduced cross-section path.

In View of the fact that pumps 10 and 10' operate as self-priming pumps, they can be utilized in a submersible sampling head and makes the same a practical method for sampling at depths say for the study of stratification of particles by sizing and counting particles at various depths involved in such study. Utilizing the system as shown in FIG. and the pump of the invention one can obtain a running study of, say particle size distribution, at various ocean depths.

What is claimed is:

1. In a centrifugal fluid pump having a hollow housing an inlet and outlet thereto and a rotatably driven impeller within the housing, the invention comprsing said impeller having an axial entrance, radial passageways communicating between the entrance and the interior of the housing and secondary axial passageways communicating between the radial pasageways and the interior of the housing in which hearing means is disposed between the impeller and the inlet, said hearing means including an outer section and an inner section having a bearing portion and axial passageway means, said impeller being fixedly mounted to a shaft and the shaft having a lesser diameter extension terminating in a tapered section and passing through said impeller and the central axial entrance thereto, said tapered section hearing against said hearing portion, and means for adjusting the clearance between the outer section and the impeller by adjustment of the relative position of said inner and outer sections from the exterior of the pump.

2. The pump as claimed in claim 1 in which hearing portion has a central recess coaxial with the axis of rotaton of the impeller and the tapered shaft portion disposed in said recess.

3. A self-priming centrifugal fluid pump comprsing a hollow housing or substantially cylndrical configuration having inlet and outlet means, a driven shaft mounted to enter said housing along a vertical axis of rotation oflset from the axis of said housing but parallel thereto, first and second bearing means coaxially arranged relative one another and said shaft, an impeller fixedly mounted to said shaft for rotation therewith, said shaft being journalled in said first hearing means and terminating through said impeller and within said second bearing means including a chamber communicating to the inlet means, said impeller having a central axial passageway communicating with said chamber, radial passageway means communicating between said central axial passageway and the interior of the housing and secondary axial passageway means spaced from the central passageway and communicating between said radial passageway means and the interior of the housing, a first fluid current path defined between said central passageway through said radial passageway means to the interior of the housing and along the vicinity of the wall thereof to the outlet means and a second fluid current path defined between said secondary aXial passageway means through said radial passageway means to the interior of the housing in the vicinity of the impeller and returning through the axial passageway means, the velocity of the first fluid current path causing the flow of fluid from the center of the impeller through the radial passageway means to the interior of the housing and into the first fluid current path. e

References Cited UNITED STATES PATENT S 1,946,212 2/1934 Jacobsen. 2,477,929 8/ 1949 Hetherington et al. 259- 2,918,017 12/ 1959 collins. 3,217,655 11/1965 Sercy et al. 103--97 FOREIGN PATENTS 1,l30,5ll 10/1956 France.

546,541 7/ 1942 Great Britain. 842,893 '7/ 1952 Germany.

HENRY F. RADUAZO, Primary Examiner U.S. Cl. X.R. 415-171 gg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. s- 9 D fed June 1970 Inventofls) OSCAR PRONI It is certified that error appers in the above-identified patent; and that said Letters Parent: are hereby corrected as shown below:

Column 6, line 26, before "including" insert said second hearing means--;

column 6, line 16, change "or" to --of--.

SIGNED AND REMI- 92 &

Sept. 22, 1970 GEAL) Anes::

Edward M. memb It. mmm x. .m.

Attesting Offce' eonnssioner ot Patents 

